Perhaps few terms in medicine have aroused so much misunderstanding, so much criticism, well-informed and ill-informed—and so much enmity as this word “psychoanalysis.” This latter fact alone, however, should not prejudice the reader for or against it. He will probably remember that it is the exception, rather than the rule, for an innovation to be received without hostility, not only from the general public, but also from experts who work in provinces bordering upon the field in which the new method is introduced. It should be pointed out that much of the heated discussion which has raged around this word psychoanalysis is due to the fact that the term has different meanings, as used, not only by its enemies, but by its friends. Psychoanalysis, according to Dr. Jung, is a _method_; “a method which makes possible the analytic reduction of the psychic content to its simplest expression, and the discovery of the line of least resistance in the development of a harmonious personality.”[48] Psychoanalysis is therefore a method of psychological analysis. Why, then, have we not used the term psychoanalysis in the earlier part of the book? It was purely to avoid unnecessary and acrimonious discussion on any particular doctrinal aspect of the question which this term may be taken to imply. It is clear to every thinking person that, in analysing a mental state the physician should use every legitimate means at his disposal. If these means include, as they do, the valuable assistance derived from the study of the patient’s dreams, his “associations” whether free or constrained,[49] and other mental phenomena, the doctor may use them freely without thereby subscribing to any one “doctrine of psychoanalysis.” The term psychoanalysis has been widely applied, not only to the diagnostic method, but also to the theories which underlie and determine the subsequent process of re-education. This seems to be a misuse of the useful word “analysis.” It may be objected that in all scientific analysis there is some directive hypothesis to be confirmed or disproved, and that in this sense all analysis is based on theory. This is true, but it seems inadvisable to confuse the analytic process with the theory which directs one form of it. When we come to consider the theoretical presuppositions which underlie the different methods of re-education adopted by various physicians, it is not surprising, at this early stage of our knowledge, to discover differences of opinion. The physician will find at every step that in “tidying up” the disentangled functions of the patient’s mentality he will need not one theory but many, for his problem is life itself.